HP XP P9500 Storage User Manual

Page 29

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Data Retention

Performance Monitor

Planning for Continuous Access Journal with multiple P9500 systems

A Continuous Access Journal system can be configured with up to four primary P9500 systems
and four secondary P9500 system. Any combination of primary and secondary systems, from one
to four, may be used.

Figure 4 (page 29)

shows an example configuration with multiple primary

and secondary systems.

Figure 4 Using Continuous Access Journal with multiple storage systems

When primary hosts write data to P-VOLs, the hosts add a time stamp to the data. Secondary
systems check time stamps and then restore data to data volumes in chronological order (older
data are restored earlier), so that data update sequence is maintained.

Please note the following when working with multiple systems:

Remote Web Console computers must be installed at primary and secondary sites.

RAID Manager should be installed on the host in both the primary and secondary sites.

Journal data is updated in the secondary systems based on the same time stamps and sequence
numbers issued by RAID Manager when the host issues the write requests to the primary
system(s). Time and sequence information remains with the data as it moves to the master and
restore journals and then to the secondary volume.

Disaster recovery operations are possible. See

“Disaster recovery when the system consists

of multiple primary and secondary storage systems” (page 94)

.

If an error occurs in a journal, it is possible that all journals may become suspended by the
error. See

“Suspension among journals ” (page 121)

for more information.

Multiple journals per RAID Manager consistency group

Normally, only one journal can be registered in a RAID Manager consistency group. With multiple
P9500 systems, however, up to four journals may be registered in a RAID Manager consistency
group in the configuration of

Figure 4 (page 29)

.

Planning for Continuous Access Journal with multiple P9500 systems

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